U.S. patent application number 16/776184 was filed with the patent office on 2020-08-20 for injectable phenol formulations and methods of their use.
This patent application is currently assigned to SAOL INTERNATIONAL LIMITED. The applicant listed for this patent is SAOL INTERNATIONAL LIMITED. Invention is credited to Imran AHMED, John DEVANE, Sharon HAMM, Leonard O'MAHONY, David PENAKE.
Application Number | 20200261377 16/776184 |
Document ID | 20200261377 / US20200261377 |
Family ID | 1000004643137 |
Filed Date | 2020-08-20 |
Patent Application | download [pdf] |
United States Patent
Application |
20200261377 |
Kind Code |
A1 |
O'MAHONY; Leonard ; et
al. |
August 20, 2020 |
INJECTABLE PHENOL FORMULATIONS AND METHODS OF THEIR USE
Abstract
Phenol formulations including phenol and an encapsulation agent,
such as a cyclodextrin or derivatives thereof, and uses of such
formulations.
Inventors: |
O'MAHONY; Leonard;
(Westmeath, IE) ; HAMM; Sharon; (Odessa, FL)
; DEVANE; John; (Dublin, IE) ; AHMED; Imran;
(Wilmington, NC) ; PENAKE; David; (Atlanta,
GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAOL INTERNATIONAL LIMITED |
HAMILTON |
|
BM |
|
|
Assignee: |
SAOL INTERNATIONAL LIMITED
HAMILTON
BM
|
Family ID: |
1000004643137 |
Appl. No.: |
16/776184 |
Filed: |
January 29, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62806188 |
Feb 15, 2019 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 9/0019 20130101;
A61P 23/02 20180101; A61K 47/40 20130101; A61K 9/0014 20130101;
A61K 31/05 20130101 |
International
Class: |
A61K 31/05 20060101
A61K031/05; A61K 47/40 20060101 A61K047/40; A61K 9/00 20060101
A61K009/00; A61P 23/02 20060101 A61P023/02 |
Claims
1. A phenol formulation, comprising: phenol, a cyclodextrin or
derivative thereof complexing at least a portion of the phenol, at
least one pharmacologically acceptable solvent.
2. The phenol formulation according to claim 1, wherein the
formulation is for injection.
3. The phenol formulation according to claim 2, wherein the
cyclodextrin is hydroxypropyl-.beta.-cyclodextrin
(HP-.beta.-CD).
4. The phenol formulation according to claim 3, wherein the
concentration of the hydroxypropyl-3-cyclodextrin is from about 10%
to about 20% by weight (w/w) of the formulation.
5. The phenol formulation according to claim 4, wherein the
concentration of the hydroxypropyl-3-cyclodextrin is from about 12%
to about 18% by weight (w/w) of the formulation.
6. The phenol formulation according to claim 5, wherein the
concentration of the phenol is from about 3% to about 9% by weight
(w/w) of the formulation.
7. The phenol formulation according to claim 6, wherein the
concentration of the phenol is about 6% by weight (w/w) of the
formulation.
8. The phenol formulation according to claim 1, wherein the
cyclodextrin is hydroxypropyl-.beta.-cyclodextrin.
9. A method for creating a nerve-block in a mammal comprising
administering an effective amount of a phenol formulation, the
formulation comprising: phenol, a cyclodextrin or derivative
thereof complexing at least a portion of the phenol, at least one
pharmacologically acceptable solvent for administration.
10. The method according to claim 9, wherein the administering is
by injection.
11. The method according to claim 9, wherein the administering is
by topical application.
12. A method for treating therapeutic, cosmetic, or tissue lysis
condition in a patient in need thereof, comprising: injecting into
or applying in proximity of a physiological target area in
proximity to or within a nerve, blood vessel, tumour, or tissue
growth of the patient an effective amount of a phenol formulation,
the formulation comprising: phenol, a cyclodextrin or derivative
thereof complexing at least a portion of the phenol, at least one
pharmacologically acceptable solvent for injection.
13. The method according to claim 12, wherein the phenol
formulation comprises from about 4% to about 9% by weight phenol,
and from about 10% to about 20% by weight cyclodextrin or
derivative.
14. A method of manufacturing a phenol composition for injection,
the method comprising: combining a cyclodextrin or derivative
thereof with a pharmacologically acceptable solvent for injection,
mixing the cyclodextrin or derivative thereof and the
pharmacologically acceptable solvent for injection until the
cyclodextrin is dissolved, adding phenol and mixing the composition
until the phenol is dissolved in the composition.
15. The phenol formulation according to claim 1, wherein the
formulation is for topical application.
Description
FIELD
[0001] This application relates to, among other things, injectable
phenol formulations and their use.
BACKGROUND
[0002] Phenol is a carbolic acid, a derivative of benzene; a
chemical with a wide variety of chemical and industrial
applications (such as plastics and herbicides). Phenol is also a
precursor agent to some pharmaceuticals, such as aspirin and has
been used directly in medical applications ranging from local
anesthetic effects to relief of skeletal muscle spasticity via
motor nerve blockade.
[0003] Phenol is a tissue non-discriminatory protein denaturing
chemical. When phenol comes in contact with protein rich tissues,
it rapidly causes damage to the tissues and eventually leads to
degeneration of the cells and protein structures, including nerves.
Given this affect, intraneural and perineural injections of phenol
have been used to cause neurolysis to treat a multitude of diseases
and syndromes, including muscle spasticity and pain. Phenol has
also been used as a non-discriminatory lysing agent for cysts,
hemorrhoids, tumors and other syndromes requiring tissue
ablation.
[0004] To obtain the desired clinical effects on skeletal muscle a
phenol solution is typically injected perineurally to a target
nerve, nerve complex, or nerve ending. Phenol chemically damages
the nerve and interferes with nerve conduction. The application of
phenol to nerves has been used effectively since the 1950s to treat
skeletal muscle spasticity, however the product has not undergone
formal safety and efficacy clinical trials, nor any formal
regulatory approval process. As a result, phenol is typically
prepared extemporaneously upon physician order through an
institutional or third-party compounding pharmacy, as a 1-10%
phenol (w/w %) aqueous or aqueous/glycerin solution, for clinical
use.
[0005] Phenol however is a non-specific toxic agent that interacts
and damages many tissues, not just nerves. This means that most
tissues which come in contact with injected phenol can also be
damaged. The current formulations of phenol, most often in aqueous
or glycerol solutions, used clinically are solutions wherein drug
that can quickly diffuse into adjacent muscle/blood vessel and
other soft tissues near the target site of injection in the
body.
SUMMARY
[0006] Provided is a novel formulation of phenol suitable for use
in humans and animals that addresses the issue of the therapeutic
index of phenol administered by injection. By "Therapeutic Index"
we mean in particular the balance between the desired therapeutic
effect (nerve block and associated effects on motor function) and
the undesirable adverse effects on local tissues (especially local
muscle and other soft tissue). The complex forming formulation
includes cyclodextrin and phenol at dose levels generally ranging
from about 30-90 mg/ml (about 3% to 9% by weight) phenol that
allows for the application of phenol to be injected perineurally to
the target nerve.
[0007] While the mechanism of action of the invention is not fully
understood, it is possible that it involves
encapsulation/complexation of all the phenol or a proportion
thereof within an inclusion complex including cyclodextrins, which
appears to reduce the immediately available free fraction of
phenol, minimizing instantaneous local tissue exposure and
potential systemic concentrations. The evidence does not seem to
suggest that the cyclodextrins are improving the solubility of the
phenol (which is what cyclodextrins are commonly used for). Based
on our findings, it appears that too much complexation compromises
efficacy and too little complexation may impair the safety profile
as represented by necrosis of the peripheral muscle tissue around
the target nerve injection site. Degeneration appeared
microscopically as irregular myofiber size and shape with
internalized nuclei, infiltrating macrophages, and increased size
and number of satellite cells. Necrosis appeared microscopically as
myofiber pallor, loss of differential staining, loss of myofiber
nuclei (hypocellularity), and fragmentation of fibers. Thus, the
complexation of phenol with a cyclodextrin appears to provide an
unexpectedly good effect by reducing local tissue damage, while
still allowing for the desired activity.
[0008] The term "complexation" is used herein to refer to the
perceived interaction between the phenol and cyclodextrin (or
derivative). It is not intended to precisely define the specific
structure formed, or to limit the manner in which
phenol/cyclodextrin interact with the tissue in the course of a
treatment with the composition. The term "encapsulation" or
"aggregation" or "inclusion complex" might also be used to describe
the nature of the interaction.
[0009] The invention provides phenol formulations, including:
phenol, a cyclodextrin or derivative thereof complexing at least a
portion of the phenol, and at least one pharmacologically
acceptable solvent. In some embodiments, the formulation is for
injection, and in some embodiments, the formulation is for topical
application.
[0010] The cyclodextrin may be, for example,
hydroxypropyl-3-cyclodextrin (HP-.beta.-CD). In some embodiments,
the concentration of the hydroxypropyl-3-cyclodextrin is from about
10% to about 20% by weight (w/w) of the formulation, such as from
about 12% to about 18% by weight (w/w) of the formulation. In some
embodiments, the concentration of the phenol is from about 3% to
about 9% by weight (w/w) of the formulation, such as about 6% by
weight (w/w) of the formulation.
[0011] The invention also provides methods for creating a
nerve-block in a mammal comprising administering an effective
amount of a phenol formulation, the formulation including phenol, a
cyclodextrin or derivative thereof complexing at least a portion of
the phenol, and at least one pharmacologically acceptable solvent
for administration. In some embodiments, the administering is by
injection, and in some embodiments, the administering is by topical
application.
[0012] The invention also provides methods for treating
therapeutic, cosmetic, or tissue lysis condition in a patient in
need thereof, by injecting into or applying in proximity of a
physiological target area in proximity to or within a nerve, blood
vessel, tumour, or tissue growth of the patient an effective amount
of a phenol formulation, the formulation including phenol, a
cyclodextrin or derivative thereof complexing at least a portion of
the phenol, and at least one pharmacologically acceptable solvent
for injection. In some embodiments, the phenol formulation includes
from about 4% to about 90% by weight phenol, and from about 10% to
about 20% by weight cyclodextrin or derivative.
[0013] The invention also provides methods of manufacturing a
phenol composition for injection, by combining a cyclodextrin or
derivative thereof with a pharmacologically acceptable solvent for
injection, mixing the cyclodextrin or derivative thereof and the
pharmacologically acceptable solvent for injection until the
cyclodextrin is dissolved, and adding phenol and mixing the
composition until the phenol is dissolved in the composition.
[0014] Additional features and advantages of the present disclosure
will be set forth in part in the description that follows, and in
part will be apparent from the description, or may be learned by
practice of the present disclosure. The objectives and other
advantages of the present disclosure will be realized and attained
by means of the elements and combinations particularly pointed out
in the description and claims.
[0015] The foregoing general description and the following detailed
description are exemplary and explanatory only to provide a further
explanation of the present disclosure and are not restrictive of
the scope of the subject matter encompassed by the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows the calculated degree of complexation of phenol
based on the concentration of HP-.beta.-CD used.
[0017] FIG. 2 is an example of a block diagram of the process used
for mixing the composition used in Example 1.
[0018] FIG. 3 summarizes the data from animal studies with a range
of cyclodextrin compositions.
[0019] FIG. 4 compares the incidence of sciatic nerve degeneration
and skeletal muscle necrosis across each group of rats when
administered with 6% (w/w) phenol formulations at 15% (w/w)
HP-.beta.-CD and viscoelastic-based formulations using HA and
NaCMC.
DETAILED DESCRIPTION
[0020] The particulars shown herein are by way of example and for
purposes of illustrative discussion of the various embodiments of
the present disclosure only, and provide what is believed to be the
most useful and readily understood description of the principles
and conceptual aspects of the disclosed subject matter. In this
regard, no attempt is made to show details of the disclosed subject
matter in more detail than is necessary for a fundamental
understanding of the disclosure, the description making apparent to
those skilled in the art how the several forms of the disclosure
may be embodied in practice.
[0021] The following disclosure refers to more detailed
embodiments, with occasional reference to the accompanying figures.
The disclosed subject matter, however, may be embodied in different
forms and should not be construed as limited to the embodiments set
forth herein.
[0022] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this disclosure belongs. The
terminology used in the description herein is for describing
particular embodiments only and is not intended to be limiting. As
used in the specification and claims, the singular forms "a," "an,"
and "the" are intended to include the plural forms as well, unless
the context clearly indicates otherwise. Also, the phrases "at
least one" and "one or more" are intended to be interchangeable,
and their use are not intended to limit the scope of any described
or claimed feature preceded by "a," "an," and "the" to a singular
form.
[0023] All publications, patent applications, patents, and other
references mentioned herein are expressly incorporated by reference
in their entirety, unless otherwise indicated.
[0024] Unless otherwise indicated, all numbers expressing
quantities of ingredients, reaction conditions, and so forth used
in the specification and claims are to be understood as being
modified in all instances by the term "about." Accordingly, unless
indicated to the contrary, the numerical parameters set forth in
the specification and claims are approximations that may vary
depending upon the desired properties sought to be obtained by a
particular embodiment. At the very least, and not as an attempt to
limit the application of the doctrine of equivalents to the scope
of the claims, each numerical parameter should be construed in
light of the number of significant digits and ordinary rounding
approaches.
[0025] Notwithstanding that the numerical ranges and parameters
setting forth the broad scope of the disclosed subject matter are
approximations, the numerical values set forth in the specific
examples are reported as precisely as possible. Any numerical
value, however, inherently contains certain errors necessarily
resulting from the standard deviation found in the method used to
obtain the value. Every numerical range given throughout this
specification includes every narrower numerical range that falls
within such broader numerical range, as if such narrower numerical
ranges were all expressly written herein.
[0026] Reference to compounds in the specification includes esters
and salts of such compounds. Thus, even if not explicitly
disclosed, such esters and salts are contemplated and encompassed
by reference to the compounds themselves.
[0027] All percent measurements in this application, unless
otherwise stated, are measured by weight based upon 100% of a given
sample weight. Thus, for example, 30% represents 30 weight parts
out of every 100 weight parts of the sample.
[0028] The present disclosure relates, in part, to a composition
comprising an active ingredient, and an agent for complexing the
active ingredient. The composition may be a pharmaceutical
composition.
[0029] A "pharmaceutical composition" as used herein means a
composition comprising an active ingredient and at least one
pharmaceutically acceptable excipient. As used herein, the term
"pharmaceutically acceptable excipient" means a compound or
ingredient that is compatible with the other ingredients in a
pharmaceutical formulation and not injurious to an intended subject
when administered in normal or therapeutically effective amounts.
As used herein, an "intended subject" includes animals and/or
humans. The terms "patient" and "subject" may be used
interchangeably.
[0030] Suitable excipients are known to those of skill in the art
and examples are described, for example, in the Handbook of
Pharmaceutical Excipients (Kibbe (ed.), 3rd Edition (2000),
American Pharmaceutical Association, Washington, D.C.), and
Remington's Pharmaceutical Sciences (Gennaro (ed.), 20th edition
(2000), Mack Publishing, Inc., Easton, Pa.), which, for their
disclosures relating to excipients and dosage forms, are
incorporated herein by reference. Examples of excipients include
but are not limited to fillers, extenders, diluents, wetting
agents, solvents, emulsifiers, preservatives, absorption enhancers,
sustained-release matrices, starches, sugars, microcrystalline
cellulose, granulating agents, lubricants, binders, disintegrating
agents, coloring agents, release agents, coating agents, sweetening
agents, flavoring agents, perfuming agents, antioxidants,
plasticizers, gelling agents, thickeners, hardeners, setting
agents, suspending agents, surfactants, humectants, carriers,
stabilizers, and combinations thereof.
[0031] The present disclosure includes a large number and variety
of components that are contemplated for inclusion in the
pharmaceutical formulations. It should be recognized that when the
inventors expressly contemplate including such components, they
also expressly contemplate excluding such components. Thus, all
components disclosed herein are expressly contemplated for
exclusion as well.
[0032] As used herein, "active ingredient" is any component of the
composition intended to furnish pharmacological activity or other
direct effect in the diagnosis, cure, mitigation, treatment, or
prevention of disease, or to affect the structure or any function
of the body of the intended subject. Active ingredients include
those components of the composition that may undergo chemical
change during the manufacture of the composition and be present in
a finished composition in a modified form intended to furnish the
specified activity or effect. Active ingredients also include those
components of the finished composition that during or after
administration of the finished drug product to the intended user
may undergo chemical change to a modified form intended to furnish
the specified activity or effect. For example, the active
ingredient can be a pharmaceutically acceptable salt of the
component that furnishes the specified activity or effect.
[0033] As used herein, the term "pharmaceutically acceptable salt"
includes salts that are physiologically tolerated by the intended
subject. Such salts are typically prepared from an inorganic and/or
organic acid. Examples of suitable inorganic acids include
hydrochloric, hydrobromic, hydroiodic, nitric, sulfuric, and
phosphoric acid. Organic acids may be aliphatic, aromatic,
carboxylic, and/or sulfonic acids. Suitable organic acids include
formic, acetic, propionic, succinic, camphorsulfonic, citric,
fumaric, gluconic, lactic, malic, mucic, tartaric,
para-toluenesulfonic, glycolic, glucuronic, maleic, furoic,
glutamic, benzoic, anthranilic, salicylic, phenylacetic, mandelic,
pamoic, methanesulfonic, ethanesulfonic, pantothenic,
benzenesulfonic (besylate), stearic, sulfanilic, alginic,
galacturonic, and the like.
[0034] As used herein, the term "prevent" or "prevention" in the
context of treatment, for example, as in "preventing spasticity" or
"prevention of spasticity" refers to a reduction in the spasticity.
In other words, as used herein, "prevention" does not require 100%
elimination of the symptom.
[0035] The composition may contain only one active ingredient, or
more than one active ingredient, such as two, three, four, five,
six, seven, eight, or nine active ingredients, or more than nine
active ingredients.
[0036] The active ingredient can be selected from among active
pharmaceutical ingredients (APIs). An API is a substance or mixture
of substances intended to be used in the manufacture of a
pharmaceutical product and that, when used in the production of a
pharmaceutical product, becomes an active ingredient of the
pharmaceutical product. Such substances are intended to furnish
pharmacological activity or other direct effect in the diagnosis,
cure, mitigation, treatment, or prevention of disease or to affect
the structure or function of the body of the intended subject. In
some embodiments, the active ingredient is phenol. In some
embodiments, the active ingredient may be alcohol or another
sclerosing agent. The active ingredient, such as phenol, can be in
any form, such as liquid, granular, powder, or micronized form.
[0037] In addition to the active ingredient, the composition
comprises a "complexing agent," such as a cyclodextrin or a
derivative thereof. Cyclodextrins are cyclic oligosaccharides
composed of a number of dextrose units of (.alpha.-1,4)-linked
.alpha.-D-glucopyranose. The cyclodextrin structures contain a
lipophilic central cavity and a hydrophilic outer surface.
Cyclodextrins can have up to six, seven, eight, or more units
(.alpha.-, .beta.-, and .gamma.-CDs have six, seven, and eight
units, respectively). Cyclodextrins are known interact with
hydrophobic drug molecules to form inclusion complexes and can be
used to improve aqueous solubility. The structure of the three most
common cyclodextrins are shown below for reference and
understanding.
##STR00001##
[0038] In the pharmaceutical industry, cyclodextrins have mainly
been used as complexing agents to increase the aqueous solubility
of active substances poorly soluble in water, in order to increase
their bioavailability and to improve stability. In addition,
cyclodextrins can be used to reduce or prevent gastrointestinal and
ocular irritation, reduce or eliminate unpleasant smells or tastes,
prevent drug-drug or drug-additive interactions within a
formulation (all these properties are based on reduction of the
free drug in solution), or to convert oils and liquid drugs into
microcrystalline or amorphous powders. (Brewster M E and Loftsson T
(2007) Cyclodextrins as pharmaceutical solubilizers. Advanced Drug
Delivery Reviews 59: 645-666.)
[0039] For .beta.-cyclodextrin, which itself has a relatively low
aqueous solubility, substitution of any of the hydrogen
bond-forming hydroxyl groups, even by lipophilic functions, results
in a dramatic improvement in the aqueous solubility of the
derivative. Examples of .beta.-CD derivatives used as excipients in
medicines include, but are not limited to, the sulfobutylether of
.beta.-CD (SBE-.beta.-CD), the hydroxypropyl derivative of
.beta.-CD (HP-.beta.-CD), and the randomly methylated .beta.-CD
(RM-.beta.-CD). The inventors contemplate the use of these
cyclodextrin derivatives, or of any other cyclodextrin derivative
that generally functions the same way in the disclosed
compositions.
[0040] The term "complexing agent" (or "complexation agent") is
used here to refer to the inventor-observed effect of the agent
seemingly preventing the phenol in the formulation from being
available for interacting with other components in the formulation,
or with the surrounding tissue on injection of the formulation.
This "complexing" effect appears to be based on an interaction
between the complexing agent and the phenol, which complex does not
appear to be caused by a covalent or ionic bond. However, some sort
of lower energy bonding phenomena, such as hydrogen bonding, or
hydrophobic interaction, may be taking place. This description does
not in any way limit the invention, and is provided simply as a
possible explanation for the phenomena observed.
[0041] In this invention, the complexing agent does not appear to
render all molecules of the phenol permanently unavailable, or
"bound." Thus, where the concentration of the phenol with respect
to the complexation agent (i.e., the phenol:complexation agent
ratio) is high, the "complexed" portion of phenol is lower. Where
the phenol:complexation agent ratio is low, the "complexed" portion
of phenol is higher. This observation is demonstrated in FIG. 1 for
hydroxypropyl-beta-cyclodextrin ("HP-.beta.-CD").
[0042] Each of the cyclodextrins shown above--.alpha.-, .beta.-,
and .gamma.-CDs--are contemplated for use in the present invention.
Additionally, derivatives of these molecules, examples of which are
well known and commercially available, are also contemplated. A
skilled person will be able to follow the present disclosure so as
to be reproduce the invention using a variety of cyclodextrin
derivatives.
[0043] In certain embodiments, only one of the noted cyclodextrins
or its derivative is used, but combinations of various
cyclodextrins may be used as well. Combinations may be useful, for
example, to produce a more complex release/complexation profile, if
desired. In this regard, each of the different cyclodextrins may
have a different ideal complexation ratio, and by using
combinations of different cyclodextrins, more complex
release/complexation profiles may be achieved.
[0044] Embodiment compositions of the present invention may be
intended for injection, and in those embodiments, other ingredients
in the compositions may be selected based on their compatibility
with other components and with the intended use. For example, a
vehicle for use in injectable compositions may include water, or
other pharmaceutically acceptable solvent. Water may be most
preferable solvent in terms of its ease of use and patient
compatibility, but the invention is not limited to the use of
water, or even to aqueous solvents, and non-aqueous solvents are
also contemplated. Topical formulations may include, for example,
other excipients that are commonly used in topical
formulations.
[0045] The dosage/concentration of the phenol in the inventive
compositions is not critical, and may be adjusted as needed by the
practitioner, based on observed results and intended use.
Concentrations in the composition may be as low as, for example,
0.1 mg/ml, such as 0.2, 0.4, 0.6, 0.8, 1, 2, 5, 10, 20, 25, 30, 35,
40, 45, 50, 55, 60, 65, 70, 75, 80, or 85 mg/ml, or any number in
between any of these values; concentrations may be as high as 900
mg/ml, such as 800, 700, 600, 500, 400, 300, 200, 150, 145, 140,
135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65,
60, 55, 50, 45, or 40 mg/ml, or any number in between any of these
values. The concentration of phenol in a composition of the present
invention is very easily adjusted and modified, and the inventors
contemplate all concentrations between these upper and lower
values--all possible fractional concentrations are not disclosed,
as doing so would be unnecessary. Embodiments may range, for
example, from about 30-90 mg/ml, or from about 40-80 mg/ml, or from
about 50-70 mg/ml, or may be about 60 mg/ml.
[0046] Similarly, the concentration of the cyclodextrin and its
derivatives (as complexing agent) may be adjusted as needed by the
manufacturer or practitioner, based on observed results and
intended use. Recognizing that the cyclodextrin and its derivatives
interact with the phenol in the composition to modify its
bioavailability, or release from the composition, the concentration
of the cyclodextrin and its derivatives will be considered with
that of the phenol so as to produce the desired result.
Concentrations in the composition may be as low as, for example,
0.25 mg/ml, such as 0.5, 1, 1.5, 2, 2.5, 5, 12.5, 25, 50, 62.5, 75,
87.5, 100, 112.5, 125, 137.5, 150, 162.5, 175, 187.5, 200, or 212.5
mg/ml, or any number in between any of these values, concentrations
may be as high as 1250 mg/ml, such as 750, 500, 375, 362.5, 350,
337.5, 325, 312.5, 300, 287.5, 275, 262.5, 250, 237.5, 225, 212.5,
200, 187.5, 175, 162.5, 150, 137.5, 125, 112.5, or 100 mg/ml, or
any number in between any of these values. The concentration of
cyclodextrin and its derivatives in a composition of the present
invention is very easily adjusted and modified, and the inventors
contemplate all concentrations between these upper and lower
values--all possible fractional concentrations are not disclosed,
as doing so would be unnecessary. Embodiments may range, for
example, from about 100-200 mg/ml, or from about 125-175 mg/ml, or
from about 140-160 mg/ml, or may be about 150 mg/ml.
[0047] Pharmaceutical compositions are typically provided in dosage
forms that are suitable for administration to an intended subject
by a desired route. Various dosage forms are described below, but
are not meant to include all possible choices. One of skill in the
art is familiar with the various dosage forms that are suitable for
use, as described, for example, in Remington's Pharmaceutical
Sciences, which has been incorporated by reference above. The most
suitable route in any given case will depend on the nature and
severity of the disease and/or condition being prevented, treated,
and/or managed. For example, pharmaceutical compositions may be
formulated for administration subcutaneously, intramuscularly,
perineurally, intraneurally, transdermally, intraarticularly,
intrathecally, intravenously, nasally, rectally, intravaginally,
intracisternally, and topically.
[0048] Pharmaceutical compositions and dosage forms described
herein may further comprise at least one additional active
ingredient other than phenol. Such additional active ingredients
may be included to treat, prevent, and/or manage the same condition
being treated, prevented, and/or managed with phenol, or a
different one. Alternatively, such additional pharmaceutical
compounds may be provided in a separate formulation and
co-administered to a subject or patient with the phenol according
to the present disclosure. Such separate formulations may be
administered before, after, or simultaneously with the
administration of the phenol.
[0049] In some embodiments, the compositions of the invention will
be stable at room temperature. As used herein, "stable" means
capable of storage without significant alteration in the
fundamental composition such that it remains usable as intended. In
some embodiments, the compositions will be stable at room
temperature; in some embodiments, the compositions will be stable
under reduced temperature conditions, such as refrigeration or
freezing. In some embodiments, the compositions are stable for one
or more days, such as a week or month or more. In some embodiments,
the compositions will include one or more additional ingredients to
improve stability, such as antioxidants.
[0050] The compositions described above can be used in methods for
treating, preventing, and/or managing various diseases and/or
conditions, comprising administering to a subject or patient in
need thereof a therapeutically effective amount of the phenol. The
phrase "therapeutically effective amount" refers to the amount of
the active ingredient (e.g., phenol), which alone or in combination
with one or more other active ingredients, provides any therapeutic
benefit in the prevention, treatment, and/or management of a
particular diseases and/or condition.
[0051] Phenol is believed to act by impairing nerve conduction via
nerve block. This can result in medical applications and cosmetic
applications. Medical applications can range from local anesthetic
to full nerve (motor and sensory) blocks that may be clinically
beneficial in conditions such as pain, skeletal muscle spasticity
and many others. The same mechanism allows phenol to be beneficial
in cosmetic indications that smooth skin or reduce wrinkles.
Finally, the lysing mechanism of phenol, unrelated to nerve block
uses, may allow for clearance of unwanted tissue, tumor lysis, and
removal of skin spots.
[0052] A particular aspect of the current invention relates to
perineural injection of motor nerves that innervate major muscles
that are subject to altered tone and associated spasticity in
patients that have incurred traumatic brain injury, spinal cord
injury or stroke. The same may be beneficial to patients with a
variety of diseases, including multiple sclerosis, cerebral palsy,
ALS, and many others.
[0053] Another particular aspect of the current invention relates
to perineural or generally local injection of phenol to sensory
nerves. The sensory nerve block may be beneficial in multiple pain
syndromes such as osteoarthritis of the knee, post-knee replacement
pain, cancer pain and neuralgias.
[0054] The inventors contemplate that a phenol formulation
according to the invention may be used for any indication for which
phenol is approved. Examples of contemplated indications include,
but are not limited to, muscle spasticity of any origin or
etiology, nerve pain, joint pain, cancer pain, osteoarthritic pain,
cosmetic uses, local anesthesia, facet joint pain, discogenic pain,
spinal stenosis, Sacro-Illiac joint dysfunction, lumbar
spondylosis, migraine related pain, occipital neuralgia,
osteosarcoma, soft-tissue sarcoma, ischemic leg pain, post-hip
arthroplasty pain, post-knee replacement pain, focal hyperhidrosis,
anismus, strabismus, hemifacial spasm, blepharospasm, cervical
dystonia, spasmodic dysphonia, sialorrhea, gustatory sweating,
facial rejuvenation, temporomandibular pain, peripheral nerve pain,
post-herpetic neuralgia, trigeminal neuralgia, chronic migraine,
glabellar lines, forehead ryetids, crow's feet, perioral lip lines,
overactive bladder, upper limb spasticity, lower limb spasticity,
carpal tunnel, fibromyalgia, rectal prolapse, post-surgical opioid
reduction, Raynaud phenomenon, hot flashes, genodermatoses,
hidradenitis superativa, pompholyx, eccrine nevus, pachynochia
congenita, aquagenic keratoderma, androgenetic alopecia, psoriasis,
darier disease, alopecia areata, hailey-hailey disease, linear IgA
dermatosis, keloids, hypertrophic scars, hereditary spastic
paraparesis, herpes zoster pain, radical mastectomy pain, complex
regional pain syndrome, spastic diplegia, spastic quadriplegia,
Morton's neuroma, post-amputation pain, phantom leg syndrome,
hypoxic eschemic cepalopathy of prematurity, pilonidal sinus
disease, neuromas, neuralgias, giant gastric leiomyomas, solid
tumor devascularization, tumor ablation, herniotic groin pain,
varicose veins, skin blemish removal, and wart removal.
[0055] The amount of the dose of the active ingredient
administered, as well as the dose frequency, will vary depending on
the particular dosage form used and route of administration. The
amount and frequency of administration will also vary according to
the age, body weight, and response of the individual subject or
patient. Typical dosing regimens and locations can readily be
determined by a competent physician without undue experimentation.
It is also noted that the clinician or treating physician will know
how and when to interrupt, adjust, or terminate therapy in
conjunction with individual subject or patient response.
[0056] Changes to the efficacy and non-targeted tissue damage may
be changed by increases or decreases in blood flow. The inventors
contemplate that an increase in blood flow of local, non-targeted
tissue may further enhance a reduction in tissue damage including
but not limited to reduction in damage to the skin or skeletal
muscle. This may be important for any application but particularly
those in areas of sensitive or thin tissues such as the face, head,
hand, feet or pubic regions for local therapeutic or cosmetic
interventions. Changes in local blood flow could be created via any
number of applications ranging from surface heating or cooling of
the local area to injection of medications that change local blood
flow.
[0057] The phenol formulation may be combined with dyes or other
agents that support visualization of the site of application.
Injectable versions of phenol may be localized with ultrasound,
electronic stimulation, fluoroscopy or other potential
visualization techniques. Dyes may also support visual localization
of the phenol following application to the skin or direct injection
while using cameras to support procedures.
[0058] The localization of the application, via injection or
otherwise, may be desired to be more targeted in areas with complex
soft-tissue structures in or near the targeted nerve or vein. In
other potential uses, particularly those that are in close
proximity to tissues such as bone like joint injections and benefit
from blocking multiple nerves may benefit from the spreading effect
that comes following injection of the phenol formulation. A
physician or other skilled clinician, having read the present
disclosure, will be able to readily determine the appropriate site
of administration, as well as the dosing and frequency thereof. In
this regard, it is not critical that the composition be injected
directly into a nerve (as doing so can sometimes result in pain);
rather, the composition can be injected or otherwise applied in a
manner that it is applied to rather than into the nerve. Stated
differently, the invention contemplates the application of the
compositions directly or indirectly to nerve tissue.
[0059] Although typically physicians have avoided the use of phenol
intravenously due to systemic exposure and toxicity concerns, this
formulation may be used intravenously or intravascularly to cause
localized vein sclerosis that may be useful in treatments of
tumors, cancer or cosmetic applications like varicose veins.
[0060] Applications of the phenol formulation on moles or other
skin spots may create a localized lysis to remove unwanted spots in
a localized and non-surgical manner. A phenol formulation may also
be used for topical use on a broader are of skin.
[0061] Typical single treatment, in potentially multiple injections
or administrations, maximum doses of phenol may be up to 1 gram per
treatment exposure. The formulation may allow for the use of phenol
beyond 1 gram of daily systemic exposure and may provide for
greater flexibility in frequency of exposure.
EXAMPLES
Example 1--Comparison of Various Strategies to Control Phenol
Release
[0062] Phenol is useful in providing a nerve-blocking effect, but
it is also generally toxic to mammalian tissue. The goal is to
provide a composition that balances phenol's ability to provide
useful nerve blockade, while minimizing local tissue destruction.
With those competing interests in mind, this example explored three
mechanistically different approaches to achieving the desired goal:
1) in situ gelling, 2) viscoelastic, and 3)
complexation/encapsulation.
Example 1A--In Situ Gelling
[0063] In situ (thermo) gelling takes advantage of the ability of
the gelling agent to react with, or change its behavior, after
injection. The example tested here is poloxamer, which is believed
to be capable of forming a gel within a certain concentration range
at mammalian body temperature.
[0064] The inventors assessed thermo-gelling polymers comprising
poloxamer 407 (P407), poloxamer 188 (P188) and/or combinations, to
determine suitable thermogelling transition temperatures
(T.sub.sol-gel). Based on available literature, P407 has a narrow
concentration range (16-20% w/w) in which T.sub.sol-gel is deemed
acceptable, however a combination of P407 and P188 have been
reported to be effective at increasing the range of viable
concentrations by up regulating T.sub.sol-gel as well as improving
the in situ dilutability of the gel.
[0065] In addition, determination of the phenol threshold levels
was assessed to assess the impact of phenol on thermo-gelling
properties of the optimal polymer/polymer blends. As phenol has the
ability to hydrogen bond, there is potential for phenol to have a
stabilizing/destabilizing effect.
[0066] A summary of the initial thermogelling properties of various
compositions is shown in Table A below.
TABLE-US-00001 TABLE A Polymer Solutions Thermogelling transition
temperatures (Poloxamer P407, P188) (T.sub.sol-gel) determined %
w/w by Malvern Kinexus Rheometer 5% P188 No 10% P188 No 15% P188 No
16% P407 29.42.degree. C. 18% P407 26.49.degree. C. 20% P407
24.35.degree. C. 10% P188 + 20% P407 38.49.degree. C. 15% P407
32.09.degree. C. 10% P188 + 16% P407 No
[0067] As can be seen in Table A above, poloxamer P188 at levels
between 5-15% were not capable of generating a T.sub.sol-gel in the
desired range of 29-36.degree. C. The combination of P188 at 10%
with P407 at different levels were not capable of generating a
T.sub.sol-gel also. Poloxamer levels of P407 in the range of 15-16%
was deemed to be the most suitable target with T.sub.sol-gel of
29.4-32.1.degree. C.
[0068] Poloxamer solutions of P407 at 15-16% were assessed in
combination with phenol at levels of 3-7.5%. Phenol was introduced
into the P407 formulation in two different ways: (1) by addition of
solid phenol fractionally, (2) solubilization of phenol in water
and subsequent dropwise addition. In both cases, formulations
gelled after addition of the phenol and remained gelled. It was
noted that there was a solubility limit of phenol as phenol was not
observed to dissolve >2% w/w in solution. In conclusion, the
solubility limit of phenol is greatly impacting the ability to
achieve the target 6% phenol levels in solution. Lower temperatures
hinder the ability to achieve >3% phenol levels. The
three-dimensional structure formed by P407 upon gelation at higher
temperature is catalysed by phenol at room temperature. Phenol has
a profound effect on poloxamer viscosity and resultant sol-gel
transition.
[0069] In situ gelling with poloxamer did not appear to be a viable
option based on the in vitro testing.
Example 1B--Viscoelastic Formulation
[0070] The second approach was to formulate the phenol with
viscoelastic components, such as hyaluronic acid (HA), and sodium
carboxymethyl cellulose (NaCMC), methylcellulose (MC), and PEG
3350, to determine if any would be an appropriate candidate. These
polymers are widely used in the pharmaceutical industry and
generally recognized as safe at concentrations that would be useful
in the present formulations.
[0071] HA in particular is a well-known ubiquitous macromolecule
found in vitreous body of eye, lubricant as synovial fluid in
joints, and extracellular matrix of the skin. HA was initially
selected, as it is a biodegradable, natural polymer with precedent
of use in injectable formulations (EUFLEXXA--sodium hyaluronate 1%
in PBS). HA is used intraocularly as a viscoelastic during cataract
extraction to protect corneal endothelium and is used as a dermal
filler and intra-articularly as injections for synovial fluid
replacement. The polymer was also considered for use as it may have
potential to ameliorate the deleterious effect of phenol while
preventing the formulation spread to peripheral tissues due to its
favourable viscoelastic and biocompatible properties.
[0072] The following tests were performed: 1) 0.1/0.5/1.0% w/w HA
with 6% w/w phenol formulation; 2) 0.5/1.0/2.0/3.0% w/w PEG 3350
with phenol; 3) blank MC formulations (0.1, 0.3, 0.5 and 1% w/w),
and challenged 0.7% and 0.9% MC with 6% w/w phenol; 4) blank CMC-Na
formulations (0.5, 1.0, 1.5 and 2% w/w), and challenged and
characterized 0.5% and 0.7% MC with 6% w/w phenol.
[0073] A summary of the formulation finds is outlined in Table
B.
TABLE-US-00002 TABLE B Sodium Hyaluronate Polyethylene glycol (HA)
Carboxymethylcellulose Methyl cellulose (PEG 3350) Aqueous
solutions Aqueous solutions Aqueous solutions PEG 3350 is exhibit
non-Newtonian exhibit non-Newtonian exhibit non-Newtonian approved
in IM based behavior (shear thinning) behavior (shear thinning)
behavior (shear thinning) formulations on the FDA 1%, 2% and 3% 1%,
1.5% and 2% 0.1%, 0.3% and 0.5% IIG database upto 3% w/w HA
formulations were too CMC-Na formulations were too MC formulations
were not Phase separation viscous to consider for viscous to
consider for sufficiently viscous was observed in further
development further development enough (<50 cP) for the
formulations with 0.5/ 0.1% and 0.5% 0.5% and 0.7% viscoelastic
approach. 1.0/2.0/3.0% w/w PEG HA with 6% phenol have CMC-Na with
6% phenol have Formation of white 3350, 7.5% w/w Phenol. adequate
viscosity and are adequate viscosity and are precipitate after
Cloudy solutions free flowing solutions free flowing solutions
challenging 0.7% and observed at 7.5% w/w during withdrawal and
during withdrawal and 0.9% MC with 6% w/w phenol injection
injection phenol Solutions of PEG 3350 up to 5% were not deemed to
be adequately viscous for this technology approach.
[0074] Based on initial testing in vitro screening (evaluating
viscosity, injectability, etc.), several HA and CMC formulations
were selected for animal testing. The selected formulations and the
justifications for their selection are shown in Table C below.
TABLE-US-00003 TABLE C Test POLYMER Article DESCRIPTION
CONCENTRATION VEHICLE JUSTIFICATION 1 Sodium Hyaluronate 0.1% w/w
WFI Lowest concentration evaluated for Na-HA that 6% (60 mg/g)
Phenol has zero shear viscosity .gtoreq. 100 cP and passed
syringeability test 2 Sodium Hyaluronate 0.5% w/w WFI Evaluated
Concentration with highest viscosity 6% (60 mg/g) Phenol to pass
syringeability test 3 Carboxymethylcellulose 0.5% w/w WFI Lowest
concentration evaluated for CMC-Na sodium that has zero shear
viscosity .gtoreq. 100 cP and 6% (60 mg/g) Phenol passed
syringeability test 4 Carboxymethylcellulose 0.7% w/w WFI Evaluated
Concentration with highest viscosity sodium to pass syringeability
test 6% (60 mg/g) Phenol
[0075] Table D below presents a summary of the histopathological
data from the HA and CMC formulations noted above, and compared to
phenol formulation as controls.
TABLE-US-00004 TABLE D Group 6: 6% Group 2: 6% Group 3: 6% Group 4:
6% Group 5: 6% Phenol, 0.7% Number Group 1: Aqueous Phenol, 0.1%
Phenol, 0.5% Phenol, 0.5% w/w w/w of Water for Phenol (active w/w
sodium w/w sodium carboxymethyl- carboxymethyl- Pathology Animals
Injection control) hyaluronate hyaluronate cellulose sodium
cellulose sodium Sciatic Nerve Total 0 10 8 8 3 3 degeneration
1> 0 2 6 7 2 2 2> 0 6 2 0 1 0 3> 0 2 0 1 0 1 Skeletal
Total 4 10 10 7 7 4 Muscle 1> 4 5 5 4 4 3 degeneration 2> 0 5
5 3 3 1 Necrosis Total 0 9 7 6 7 3 1> 0 5 2 4 5 3 2> 0 4 3 1
2 0 3> 0 0 2 1 0 0 Clinical Signs No signs 1 hr post dose: 1 hr
post dose: 1 hr post dose: 1 hr post dose: 1 hr post dose: from
1-48 mild paresis mild paresis mild paresis mild paresis mild
paresis hours (8/10), (8/10), (5/10), moderate (6/10), moderate
(6/10), moderate moderate moderate paresis (2/10), paresis (1/10),
paresis (3/10), paresis (2/10), paresis (1/10), decreased digit
decreased digit decreased digit decreased digit decreased digit
abduction (7/10) abduction (7/10) abduction (9/10) abduction
abduction (9/10) 4 hr post dose: 4 hr post dose: 4 hr post dose:
(10/10) 4 hr post dose: mild paresis mild paresis mild paresis 4-48
hr post dose: mild paresis (7/10), (7/10), (6/10), moderate dose:
mild (9/10), decreased digit decreased digit paresis (3/10),
paresis (9/10), decreased digit abduction (8/10) abduction (7/10)
decreased digit moderate abduction (9/10) 24 hr post dose: 24 hr
post dose: abduction (9/10) paresis (1/10), 24 hr post dose: mild
paresis mild paresis 24 hr post dose: decreased digit mild paresis
(6/10), moderate (6/10), decreased mild paresis abduction (10/10)
(8/10), moderate paresis (1/10), digit abduction (8/10), decreased
paresis (1/10), decreased digit (7/10) digit abduction decreased
digit abduction (8/10) 48 hr post dose: (8/10) abduction (9/10) 48
hr post dose: mild paresis 48 hr post dose: 48 hr post dose: mild
paresis (6/10), decreased mild paresis mild paresis (6/10),
moderate digit abduction (8/10), decreased (9/10), paresis (1/10),
(6/10) digit abduction decreased digit decreased digit (9/10)
abduction (9/10) abduction (8/10) Macroscopic No signs Mild redness
at Mild redness at Mild redness at Mild redness at Mild redness at
observations at (10/10) injection site injection site injection
site injection site injection site time of tissue (7/10), (6/10),
no signs (5/10), moderate (6/10), no signs (7/10), no signs
collection moderate (4/10) redness (1/10), (1/10) (3/10) redness
(1/10), no signs (4/10) no signs (2/10)
[0076] FIG. 4 compares the incidence of sciatic nerve degeneration
and skeletal muscle necrosis across each group of rats when
administered with the lead 6% w/w phenol formulations at 15% w/w
HP.beta.CD and the alternate viscoelastic based formulations using
HA and NaCMC polymers at the two levels (shown in Table D above).
In the Figure, nerve degeneration is deemed to be desirable, and
skeletal muscle necrosis undesirable. Thus, the better performing
formulations have the greatest difference between these results. As
can be seen in FIG. 4, the viscoelastic based formulations were
deemed to be inferior to the cyclodextrin based formulation with
respect to sciatic nerve degeneration effects relative to the
minimization of skeletal muscle necrosis.
[0077] This finding--that the cyclodextrin and its derivatives
would prove to be the best of the three initial choices (in situ
gelling, viscoelastic, and complexation/encapsulation) is
surprising in and of itself. In this regard, the inventors
initially had no particular preference or belief that one of the
three possible candidate strategies would be any better than any
other strategy--there were no published studies available to
explain how phenol would be released or otherwise become available
in vivo to interact with surrounding tissue from these
formulations. In fact, if anything, the viscoelastic formulation
using hyaluronic acid was probably the most attractive given that
it is naturally occurring in mammals and has been used
pharmaceutically as a viscosity modifying agent. There was nothing
to initially suggest that complexation/encapsulation would provide
a different, not to mention better, result than the other
formulations.
Example 2--Dosing Studies Using Phenol and Various
Cyclodextrins
[0078] The formulations presented in Table 1 and Table 3 were
manufactured as per the manufacturing process outlined in FIG. 2
and then screened in a rodent sciatic nerve block model, where 0.2
mls phenol/rat was administered caudal to the sciatic notch of the
pelvis in the right hind limb as a perineural injection. The dose
and volume injected were selected based on data from previous
sciatic nerve block studies (Reference Appendix 1 for a detailed
overview of non-clinical studies and conclusions).
TABLE-US-00005 TABLE 1 Prototype 6% Aqueous 6% Phenol, 20% 6%
Phenol, 40% 9% Phenol, 40% 6% Phenol, 20% Phenol
Hydroxypropyl-.beta. Hydroxypropyl-.beta. Hydroxypropyl-.beta.
Hydroxypropyl-.gamma. (control) Cyclodextrin Cyclodextrin
Cyclodextrin Cyclodextrin Appearance Clear Clear colorless Clear
colorless Clear colorless Clear colorless colorless solution, free
of solution, free of solution, free of solution, free of solution
visible particulates visible particulates visible particulates
visible particulates pH 3.6 6.4 6.8 6.6 5.8 Viscosity -- 2.8 13.5
15.7 2.7 (cSt) Osmolality 551 466 342 392 390 (mOsm/kg) Assay 99.3%
104.5% 112.7% 112.4% 104.8% Particulate Confirms Confirms Confirms
Confirms Confirms matter (HIAC) .gtoreq.10 .mu.m 366 64 92 31 90
NMT 6000 .gtoreq.25 .mu.m 18 1 29 12 0 NMT 600 Syringe- -- Free
flowing Slow viscous Slow viscous Free flowing ability solution
during withdrawal and withdrawal and solution during (25G
withdrawal and free flowing free flowing withdrawal and needle)
injection injection injection injection
TABLE-US-00006 TABLE 3 Prototype 6% Aqueous 6% Phenol, 10% 6%
Phenol, 12.5% 9% Phenol, 15% 6% Phenol, 17.5% Phenol
Hydroxypropyl-.beta. Hydroxypropyl-.beta. Hydroxypropyl-.beta.
Hydroxypropyl-.beta. (control) Cyclodextrin Cyclodextrin
Cyclodextrin Cyclodextrin Appearance Clear Clear colorless Clear
colorless Clear colorless Clear colorless colorless solution, free
of solution, free of solution, free of solution, free of solution
visible particulates visible particulates visible particulates
visible particulates pH 3.6 5.9 6.0 6.1 6.2 Viscosity -- 1.6 1.8
2.1 2.3 (cSt) Osmolality 551 473 454 460 456 (mOsm/kg) Assay 99.3%
98.8% 99.8 100.7 101.8 Particulate Confirms Confirms Confirms
Confirms Confirms matter (HIAC) .gtoreq.10 .mu.m 366 20 16 26 26
NMT 6000 .gtoreq.25 .mu.m 18 0 0 4 4 NMT 600 Syringe- -- Free
flowing Free flowing Free flowing Free flowing ability withdrawal
and withdrawal and withdrawal and withdrawal and (25G ini ection
injection injection injection needle)
[0079] The animals were observed pre-dose and at periodic intervals
over a 48-hour period for target hind limb paresis, ataxia and
abnormal posture. Additionally, pain measurement and motor activity
were performed. Necropsy was performed on animals 48 hours post
injection and target nerve and muscle tissue samples adjacent to
the injection site were collected and processed for
histopathological evaluation (e.g. assessment of the degree of
nerve sciatic degeneration and local skeletal muscle degeneration
and necrosis). Macroscopic observations of edema, erythema and
irritation at the dermal site of needle insertion was also
performed.
[0080] Table 2 provides a summary of the histopathological
evaluation associated with formulations presented in Table 1. In
summary, by the complexation of phenol with CDs (HP .beta. and
HP-.gamma.-CDs), one can observe a noticeable reduction in the
number of animals with local skeletal muscle necrosis as compared
to the standard 6% aqueous phenol solution, whilst achieving
effective sciatic nerve degeneration. This latter observation was
matched by `clinical` effects on the animal hind limbs, including
paresis and digit abduction.
TABLE-US-00007 TABLE 2 Group 1: Number Water for Group 3: 6% Group
4: 6% Group 6: 6% of Injection Group 2: 6% Phenol, 20% Phenol, 40%
Group 5: 9% Phenol Phenol, 20% Pathology Animals (control) Aqueous
Phenol HP-.beta. CD HP-.beta. CD 40% HP-.beta. CD HP-.gamma. CD
Sciatic Nerve Total 0 10 8 0 6 10 degeneration 1> 0 2 6 0 6 6
2> 0 6 2 0 0 3 3> 0 2 0 0 0 1 Skeletal Muscle Total 3 10 9 9
8 10 degeneration 1> 3 5 4 8 5 4 2> 0 5 5 1 2 4 3> 0 0 0 0
1 2 Total 0 9 4 1 3 7 Necrosis 1> 0 5 2 1 2 2 2> 0 4 2 0 0 5
3> 0 0 0 0 1 0 Clinical Signs No signs 1 hr post dose: 1-4 hr
post 1-4 hr post 1 hr post dose: mild mild paresis from 1-48 mild
paresis dose: mild dose: slight paresis (4/10), (10/10), hours
(8/10), paresis (9/10), paresis moderate paresis decreased moderate
decreased digit (1/10), 24-48 (1/10), slight paresis digit paresis
(2/10), abduction hr post dose: (1/10), decreased digit abduction
decreased digit (9/10) no signs abduction (5/10), (10/10) abduction
24-48 hr post intermittent twitching (10/10) dose: mild (1/10) 4-48
hr post paresis (8/10), 4 hr post dose: mild dose: mild decreased
digit paresis (5/10), slight paresis (9/10), abduction paresis
(2/10), moderate (8/10) decreased digit paresis, abduction (5/10)
decreased digit 24-48 hr post dose: abduction (10/10) mild paresis
(5/10), decreased digit abduction (5/10) Macroscopic No signs Mild
redness at Mild redness at Mild redness Mild redness at Mild
redness observations at (10/10) injection site injection site at
injection injection site (2/10), at injection time of tissue
(7/10), moderate (6/10), site (2/10), moderate redness site (8/10),
collection redness (1/10), moderate no signs (1/10), no signs
(6/10) no signs no signs (2/10) redness (1/10), (8/10) (2/10) no
signs (3/10)
[0081] Table 4 below provides a summary of the histopathological
evaluation associated with formulations manufactured with
incremental increases in the dose level of HP .beta. CD from 10%
w/w to 17.5% w/w (Refer to Table 3) based on the learnings from the
initial prototype screen as outlined in Table 2.
TABLE-US-00008 TABLE 4 Group 2: 6% Number Group 1: Aqueous Group 3:
6% Group 4: 6% Group 5: Group 6: 6% of Water for Phenol (active
Phenol, 10% Phenol, 12.5% 6% Phenol Phenol, 17.5% Pathology Animals
Injection control) HP-.beta. CD HP-.beta. CD 15% HP-.beta. CD
HP-.beta. CD Sciatic Nerve Total 0 10 10 10 10 10 degeneration
1> 0 2 2 0 3 3 2> 0 6 4 4 2 4 3> 0 2 4 6 5 3 Skeletal
Total 3 10 7 7 9 9 Muscle 1> 3 5 7 6 8 9 degeneration 2> 0 5
0 1 1 0 Necrosis Total 0 9 9 7 5 6 1> 0 5 0 3 0 0 2> 0 4 2 2
1 5 3> 0 0 7 2 4 1 Clinical Signs No signs 1 hr post dose: 1 hr
post 1 hr post 1 hr post dose: 1 hr post dose: from 1-48 mild
paresis dose: mild dose: mild slight paresis (1/10), mild paresis
hours (8/10), paresis (6/10), paresis (6/10), mild paresis (7/10),
(7/10), moderate moderate moderate moderate moderate paresis
paresis (2/10), paresis (2/10), paresis (3/10), paresis (3/10),
(2/10), decreased decreased digit decreased digit decreased digit
decreased digit digit abduction abduction abduction abduction
abduction (9/10) (9/10) (10/10) (9/10) (9/10) 4-24 hr post dose:
4-24 hr post 4-48 hr post 4-48 hr post 4-24 hr post slight paresis
(1/10), dose: mild dose: mild dose: mild dose: mild mild paresis
(8/10), paresis (8/10), paresis (9/10), paresis (8/10), paresis
(7-8/10), moderate paresis moderate paresis moderate moderate
moderate (1/10), decreased (1/10), decreased paresis, paresis
(1/10), paresis (1-2/10), digit abduction digit abduction decreased
digit decreased digit decreased digit (9/10) (9/10) abduction
abduction abduction 48 hr post 24-48 hr post (10/10) (9/10) (9/10)
dose: mild dose: mild paresis (8/10), paresis (8-9/10), decreased
digit decreased digit abduction abduction (8/10) (8-9/10)
Macroscopic No signs Mild redness at Mild redness at Mild redness
Mild redness Mild redness observations at (10/10) injection site
injection site at injection at injection at injection site time of
tissue (7/10), moderate (6/10), site (5/10), severe site (9/10),
(6/10), moderate collection redness (1/10), moderate redness (1/10)
no signs (1/10) redness (2/10), no signs (2/10) redness (1/10), no
signs (3/10) no signs no signs (3/10) (2/10)
[0082] One can observe a noticeable reduction in the number of
animals with local skeletal muscle necrosis between the range of
15-17.5% w/w HP .beta. CD as compared to the standard 6% aqueous
phenol solution without complexing agent, whilst achieving
effective sciatic nerve degeneration. There is a dose-dependent
relationship observed where the number of animals exhibiting muscle
necrosis increases as the level of HP .beta. CD decreases below
12.5% w/w (see FIG. 3).
[0083] A surprising observation from the histopathology data was
that at comparable % (w/w) CD to phenol, the 20% HP .beta. CD and
20% HP-.gamma.-CD resulted in different therapeutic improvement
effects. Another surprising observation was that an increase in %
CD (w/w) to phenol from 20% to 40% had a dramatic effect in
reducing efficacy but improving local safety. A further surprising
effect was that increasing the free fraction of phenol for the 20%
HP .beta. CD (9% total phenol) did not match the standard 6% phenol
effect but did show some signs of systemic toxicity.
Example 3--Further Studies Using Phenol and Cyclodextrin
[0084] Further studies were performed to evaluate various other
dosing considerations. The details and results of the studies are
summarized in Table 5 below.
[0085] Briefly, for the studies summarized in Table 5 below, all
were single dose perineural injection studies in Sprague Dawley
rats, which consisted of 8 to 10 animals per group. Animals were
dosed with solutions of phenol and vehicle (supplied by Alcami
Corporation, 2320 Scientific Park Dr., Wilmington, N.C. 28405).
Sterile water for injection (WFI) was used as a vehicle control for
these studies.
[0086] Clinical observations were made at pre-dose and 1, 4, 24,
and 48 hours after dosing for paresis, ataxia and abnormal posture.
Observations were made at .+-.5 minutes for the 1-hour post-dose
observations and .+-.15 minutes for the later observations. The
pain threshold of the hind paw of the injected side was measured
immediately following the clinical observations at approximately 1,
4, 24, and 48 hours after dosing. Animals were then placed in a
photobeam activity system at approximately 1, 4, 24, and 48 hours
post dose for 5 minutes to assess spontaneous motor activity. A
necropsy was performed and nerve and muscle tissue samples adjacent
to the injection site were collected and processed for
histopathological evaluation. The collected tissues were preserved
in 10% neutral buffered formalin (NBF) and evaluated for
histopathological changes.
Table 5 (Below, Next Page)
TABLE-US-00009 [0087] Study Title Objective/Description Dose
Duration Results Effect of Phenol To identify the preferred 60
mg/mL aqueous 48 hrs Injection volume over 0.2 mL saturates
Administered volume to be used in the Phenol @ 0.1, 0.2, the tissue
peripheral to the target site. Perineurally on perineural injection
caudal 0.3, 0.4 and 0.5 mL/rat All subsequent studies focused on a
volume Sciatic Nerve to the sciatic notch of the of 0.2 mL.
Function in Rats hind limb Effect of Phenol To evaluate the target
dose 60 mg/mL and 48 hrs No significant dose-dependent effects were
Administered range to be used in the 75 mg/mL aqueous observed
across the range assessed Perineurally on perineural injection
caudal Phenol @ 0.2 mL/rat Sciatic Nerve to the sciatic notch of
the Function in Rats hind limb A Four Week Study To evaluate the
preferred 60 mg/mL aqueous 28 days Over 28 days, time-dependent
microscopic of Sciatic Nerve dose and injection volume Phenol @ 0.2
mL/rat alterations in the sciatic nerve and skeletal Function After
a to produce an effective muscle tissues Single Perineural block of
the sciatic nerve Myofascial inflammation/fibroplasia/granulation
Injection of function and to assess the tissue with or without
subjacent myofiber Aqueous Phenol effects of the nerve block
regeneration was noted through Day 21, with Solution in Rats on the
sciatic nerve function complete recovery by Day 28 and surrounding
tissue over Sciatic nerve fibroplasia/inflammation/hemorrhage this
28 day period (epineurial) with pronounced axonal degeneration and
regeneration were present on Day 7, with total resolution of the
epineurial alterations and ongoing recovery of the axonal effects
noted by Day 28 Effect of Phenol To evaluate the ability of 6% (60
mg/ml) aqueous 48 hrs 6% Phenol/20% HP.beta.CD formulation
demonstrated Formulations four phenol prototype phenol solution
enhanced safety profile with comparable clinical Administered
formulations administered 6% (60 mg/g or 64 mg/ml) effect as
reported from the histopathologic Perineurally on by perineural
injection to phenol prepared in 20% analysis of the animal tissues
Sciatic Nerve evaluate its ability to block HP.beta.CD solution The
degree of sciatic nerve degeneration and Function in Rats the
sciatic nerve function. 6% (60 mg/g or 68.4 mg/ml) skeletal muscle
degeneration was comparable phenol prepared 40% however there was a
significant reduction in HP.beta.CD solution the number of animals
with reported skeletal 9% (90 mg/g or 102.4 mg/ml) muscle necrosis
of phenol prepared in 40% HP.beta.CD solution and 6% (60 mg/g or
64.2 mg/ml) of phenol prepared in 20% HP.gamma.CD solution Effect
of Phenol To evaluate the ability of 6% (60 mg/g or 63 mg/ml) 48
hrs Each formulation caused mild to moderate paresis Formulations
four phenol prototype phenol/(10%) 103.2 mg/ml Degeneration and
inflammation with less frequent Administered formulations (with
varying HP.beta.CD solution hemorrhage were noted in the sciatic
nerves while Perineurally on concentrations of HP.beta.CD 6% (60
mg/g or 63 mg/ml) myofiber necrosis/degeneration usually
accompanied Sciatic Nerve (10-17.5%) administered by phenol/(15%)
157.4 mg/ml by inflammatory cell infiltrates, edema, and Function
in Rats - perineural injection to HP.beta.CD solution hemorrhage
was present in skeletal muscle Study 2 evaluate its ability to
block 6% (60 mg/g or 63 mg/ml) A slight increase in the
incidence/intensity of the sciatic nerve function. phenol/(17.5%)
184.9 mg/ml myofiber necrosis in the skeletal muscle was HP.beta.CD
solution observed in animals injected with 63 mg/mL phenol 6% (60
mg/g or 63 mg/ml) solution/10% HP.beta.CD solution, as compared to
phenol/(12.5%) 130.1 mg/ml the other test article treatment groups
HP.beta.CD solution Based on the results from previous studies,
formulation of 6% (63 mg/mL) Phenol prepared in 15% (157.4 mg/mL)
HP.beta.CD solution is planned to use in future studies based on
reported sciatic nerve degeneration whilst minimizing skeletal
muscle necrosis and skeletal muscle degeneration. Effect of Phenol
To evaluate the ability of 6% (60 mg/g or 60.3 mg/ml) 48 hrs The
perineural administration of the injected 6% Formulations several
phenol viscoelastic phenol/0.1% w/w Sodium w/w phenol/0.1% w/w
Sodium hyaluronate solution Administered formulations administered
by hyaluronate and 6% w/w phenol/0.7% w/w Carboxymethyl-
Perineurally on perineural injection to 6% (60 mg/g or 60.3 mg/ml)
cellulose sodium caused mild to moderate paresis Sciatic Nerve
evaluate its ability to block phenol/0.5% w/w Sodium and decreased
digit abduction in most animals at Function in Rats - the sciatic
nerve function. hyaluronate all timepoints. Incidence of clinical
signs after Study 3 6% (60 mg/g or 60.3 mg/ml) perineural
administration appeared to be lower phenol/0.5% w/w with 6% w/w
phenol/0.5% w/w Sodium hyaluronate Carboxymethylcellulose solution
or 6% w/w phenol/0.5% w/w Carboxymethyl- sodium cellulose sodium.
6% (60 mg/g or 60.4 mg/ml) Microscopic examination of injection
sites post phenol 0.7% w/w injection revealed test article minimal
to moderate Carboxymethylcellulose focal segmental degeneration of
sciatic nerve axons sodium and focal monophasic degeneration and
necrosis of skeletal muscle fibers with a secondary inflammatory
response in all groups receiving test articles. Axon degeneration
and myofiber degeneration and necrosis were modestly reduced in
incidence among rats receiving the 6% w/w phenol/0 7% w/w Carboxy-
methylcellulose sodium as compared to the other three treatment
groups.
[0088] The present disclosure includes any combination of these
various features or embodiments above and/or below as set forth in
sentences and/or paragraphs. Any combination of disclosed features
herein is considered part of the present disclosure and no
limitation is intended with respect to combinable features.
[0089] Applicant specifically incorporates the entire contents of
all cited references in this disclosure. Further, when an amount,
concentration, or other value or parameter is given as either a
range, preferred range, or a list of upper preferable values and
lower preferable values, this is to be understood as specifically
disclosing all ranges formed from any pair of any upper range limit
or preferred value and any lower range limit or preferred value,
regardless of whether ranges are separately disclosed. Where a
range of numerical values is recited herein, unless otherwise
stated, the range is intended to include the endpoints thereof, and
all integers and fractions within the range. It is not intended
that the scope of the disclosure be limited to the specific values
recited when defining a range.
[0090] Other embodiments of the present disclosure will be apparent
to those skilled in the art from consideration of the present
specification and practice of the present disclosure disclosed
herein. It is intended that the present specification and examples
be considered as exemplary only with a true scope and spirit of the
disclosure being indicated by the following claims and equivalents
thereof.
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